An impact damper is used for positioning a bumper member on the framework of a vehicle. The impact damper is dimensioned such that it damps impacts up to a predetermined impact velocity of the vehicle with respect to the obstacle. This predetermined velocity is e.g. 8 km/h. At a higher impact velocity the impact damper behaves like a rigid unit because the flow resistance between the respective fluid chambers of the impact damper is too high. As the impact damper is fastened to the framework of the vehicle, a high velocity impact is substantially rigidly transmitted to the framework and a considerable deformation of the framework occurs. The preset deformation zones of the vehicle cannot become effective to absorb part of the impact energy because the impact is directly and rigidly transmitted to the framework of the vehicle without the preset deformation zones being involved in absorbing the impact energy. Most sensitive parts of the vehicle are frequently mounted on the framework to which also the impact damper is fastened too. As a result of the damage to the framework resulting from the rigid behavior of the impact damper, these sensitive parts of the vehicle are also damaged.